Half-Life 2

Half life 2 Mods don't work for meEither nothing happens or an error comes upI have tried it on mods like the hidden and opposing force 2 I put the mods in the sourcemods flder but they won't workPlease help

It's due to the change in file types and file structure by Steam, "SteamPipe". Which basically ruined any mod made prior to the change, or "upgrade" as they would have you believe, but in fact I did a comparison of the current HL2 and a past version and noted very little "difference" <spoken like G-Man>. There are instructions for how to get old mods to work, but so far all of them I have tried and I still get the "Launcher DLL missing error".